JPS61157647A - Manufacture of aluminum quality strengthened composite material - Google Patents

Abstract

PURPOSE:To develop the titled material superior in various characteristics, by adding and permeating pressedly molten Al or Al alloy, to material in which solid particles for strengthening material are adhered and mixed into wool ball shaped inorganic fiber materials. CONSTITUTION:Inorganic fibers having 1-10mum diameter such as fibers of alumina, carbon, ceramic are dispersed and stirred in water to form wool ball shaped coagulation particles having 0.5-10mm diameter in >=90% thereof. Granular solid particles such as C, Pb, Si3N4, Al2O3, SiC as strengthening solid particle having 1-100mum diameter in >=80% thereof are added, mixed into said wool ball shaped particles by about 0.1-3 times ratio, and the mixture is pressed in a suitable metal vessel. Molten Al or Al alloy is added thereto, these are pressed, permeated and solidified to manufacture the titled material superior in physical, mechanical properties such as high temp. strength, wear resistance, thermal expansion coefft.

Description

[Detailed Description of the Invention] ``Object of the Invention'' The present invention relates to a method for manufacturing an aluminum reinforced composite material, in which fibers and particulate reinforcing materials are uniformly dispersed in an aluminum matrix and are tightly bound and integrated. The aim is to provide a method for obtaining aluminum reinforced composite materials.

Industrial applications Manufacturing technology for aluminum reinforced composite materials.

Conventional Technology As weight reduction and miniaturization of various products and components have become important issues, the requirements for properties of aluminum alloys etc. have become increasingly strict, especially high temperature strength,
There is a growing demand for better wear resistance and thermal expansion properties, and in order to satisfy these physical and mechanical properties, it is necessary to simply add other metals to aluminum, or to cast it. It is insufficient to improve properties by changing the morphology of the matrix, crystallized substances, precipitates, etc. by devising heat treatment methods, etc., and recently, reinforced composite methods that add particle reinforcements have been adopted. It is being done. However, in order to obtain this particle-reinforced composite material, a powdered matrix material is usually mixed with powdered reinforcing particles in accordance with the powder metallurgy method, but the process is not only complicated, but also requires a large amount of powder, which is the raw material. is not suitable for mass production because it is expensive.

Therefore, in JP-A No. 5, it was proposed to stir a semi-molten aluminum alloy and mix it with powder such as alumina.
It is announced in the publication No. 7-82440.

Furthermore, Japanese Patent Application Laid-Open No. 55-24949 proposes that graphite particles are added to a molten alloy of No. 81, stirred and suspended, and then solidified under pressure.

Problems to be Solved by the Invention However, even the method disclosed in Japanese Patent Application Laid-Open No. 57-82440 has disadvantages such as difficulty in stirring and temperature control, large variations, and difficulty in obtaining uniform performance.

Moreover, in the method according to JP-A No. 55-24949, the difference in specific gravity,
Molten metal (IJ) due to the effects of surface tension, wettability, etc.
Separation from the socked particles occurs, making it difficult to form a uniform mixed state as described above, making it impossible to effectively obtain the desired properties.・ "Structure of the Invention" Means for solving the problem A step of preparing an inorganic fiber material as flocculent aggregates,
Particles with a particle size of 1 to 100μ are added to the
% or more, a step of adhering and mixing the reinforcing material particles, and a step of adding a molten metal of aluminum or aluminum alloy to the bulbous fiber material to which the reinforcing material particles have been adhering and mixed, and passing it through under pressure. A method for producing quality-reinforced composites.

Function: Since the inorganic fiber material is formed into spherical agglomerated particles, it can be easily mixed and adhered with powdery property reinforcing material particles, and a uniform mixed and adhered state can be formed.゛80% of the property reinforcement particles have a particle size of 1 to 100 μm.
By preparing as described above, it is possible to effectively and uniformly enter the hair globular fiber agglomerated grains and adhere to the peripheral surface thereof.

As mentioned above, aluminum or aluminum alloy molten metal is added to a state in which property reinforcing material particles are uniformly dispersed using a bulbous inorganic fiber material as a medium, and the property reinforcing material particles are uniformly dispersed by applying pressure and permeating the aluminum. Accurately obtain quality composite materials.

EXAMPLE To explain the embodiment of the present invention, in order to uniformly disperse the above-mentioned property-enhancing particles and to avoid their separation, alumina fibers and other inorganic fiber materials are prepared in the form of bulbs. The reinforcing particles are dispersed using the bulb-like fiber material as a medium. In addition to alumina fibers, the fiber materials include ceramic fibers, carbon fibers, etc., and the diameter of such inorganic fibers is 1 to 1.
The thickness is preferably about 10 μm. To adjust the shape of a hair ball, for example, mills, bulk, or matte alumina staple fibers are dispersed and stirred in water, and then the fibers are made into a ball shape.However, simply stirring in water and then forming the hair into a ball shape results in irregular sizes. Because of this, it is further massaged to reduce the size of the hair bulb, and more than 90% of the hair is 0.
．． Shape into a bulb with a diameter of 5 to 101111 mm. Reducing the diameter of the bulb in this way is important in order to make the distribution of fibers and reinforcing particles in the composite material as uniform as possible. Saluyl alumina fibers are easy to handle and heat resistant.
The diameter of the hair bulb can be appropriately reduced by the adjustment operation described above.
It also has high tensile strength, so it can be advantageously used.

Reinforcing particles are mixed and stirred into the bulbous fibers prepared as described above. When a hair bulb made of fibers with a diameter of about 3 μm is used as described above, the solid particles of the property-enhancing material having a diameter of about 5 μm or less can properly penetrate into the hair bulb and be dispersed, and the solid particles with a diameter of about 10 μm or more can be dispersed. The reinforcing particles that do have a tendency to adhere to the outer portion of the hair bulb. The solid reinforcing particles generally need to be adjusted such that 80% or more are between 1 and 100 μm, so that they are not dispersed only within the hair bulb or only in the outer part. That is, this particle size is 1 μm.
If the following materials are used, the composite coagulum becomes friable and the resulting composite material becomes brittle, making it impossible to obtain a reinforced composite material as the object of the present invention. Can not. In other words, it is presumed that when the particle size is small like this, the wettability with the molten metal is poor, and when it solidifies, it adheres to the aluminum crystal grain boundaries, exhibiting a mold release effect and exhibiting understandability. If the number of fine particles of 1 μm or less is reduced, the particles are distributed in a well-wetted state within the aluminum crystal grains, and in this case, no decomposition property is exhibited. In addition, if a large amount of large particles with a particle diameter of 100 μm or more is included, the processability of extrusion processing, cutting processing, etc. after compounding will be poor, and the performance of the composite material will also deteriorate. Stress concentration occurs, causing cracks during machining, and deterioration of mechanical properties. Particularly during machining, hard spots form and cause tool breakage.

The reinforcing solid particles used include those with light specific gravity such as carbon particles, those with heavy specific gravity such as lead particles, and S
It is widely effective against particles that are difficult to wet with aluminum, such as i, nitrogen particles, and particles that diffuse and dissolve in molten aluminum, such as metal Si particles. As non-metallic particles, S
In addition to i3N4 and graphite, there are SiC, A1□03, etc.
Metal particles having a melting point higher than that of aluminum can be infiltrated with molten aluminum alloy and then cooled quickly to obtain a particle composite. It is clear that even metal particles having a melting point lower than that of aluminum can be appropriately obtained as a particle composite material if the metal does not melt in aluminum, such as PB.

Regarding the composite ratio in the composite material, a mixture of bulbous fibers and reinforcing material particles can be appropriately placed in a case and compressed to form a predetermined composite ratio relationship. It can be implemented over a wide range such as 30%,
It is possible to mix solid particles into this and adjust the solid particles to an appropriate ratio within the range of 0.1 to 3 times the volume of the bulbous fibers.

That is, if the reinforcing solid particles are less than 0.1 times as large as the hair spherical fibers, the reinforcing effect of the particle composite is poor, and when it is 3 times or more, a layer of solid particles separated from the hair spherical fibers is formed.
The composite material becomes non-uniform. The combined volume percentage of the bulbous fibers and the reinforcing solid particles is appropriately selected in the range of 3.3% to about 40%, and such volume percentage ensures that the processability and performance of the resulting composite material are appropriately controlled. It is determined.

As mentioned above, a mixture of bulbous fibers and reinforcing solid particles is placed in a case and compressed to a predetermined volume percentage, then heated to a temperature higher than the melting point of the aluminum alloy, and molten aluminum alloy is added to it. The material is infiltrated and solidified by applying a pressure of about 3 kg/cIT12 or more using the hot forging method or centrifugal force method.

In order to make the composite material thus obtained into a product shape, it is made into a product shape from a case shape, or it is made into a lump shape and then subjected to an extrusion, forging or rolling process to be made into a product shape.

A specific manufacturing example of the product according to the present invention will be described below.

Bulk short alumina fibers with a length of approximately 10 m and a diameter of approximately 3 μm were placed in water, stirred for approximately 2 hours using a stirrer with an impeller, dehydrated using a vacuum turbulator, and then placed in a drying chamber for further dehydration. Then, it was made into a hair spherical fiber material, which was then further loosened to obtain a hair spherical fiber material with a diameter of about 2 to 5 mm.

On the other hand, various types of reprint particles having particle size distributions as shown in Table 1 below were prepared.

However, the capacity % shown in the following Table 2 is 100φX1
In order to make a 20111 length fin and throat, the required weight was measured and the mixture was placed in a ■-shaped mixer and mixed to uniformly adhere the particles inside the bulb.

Each of the mixtures thus obtained was placed in an iron cylindrical case with an eave of 100φ x 300mm length, and the mixture of light bulb-shaped fiber material and particles was heated to a height of 120n+ using a plunger so as to achieve a predetermined Vf. I compressed it until it became.

Items placed in the case were preheated in this way,
The preheating temperature was set at 850°C for graphite and 5i3Na since their wettability was poor, and at 800°C for the others. During this preheating, the lead powder and graphite powder were covered with a lid to prevent oxidation.

If the product is preheated as described above,
A molten metal of IS A6061 alloy was charged and infiltrated under pressure using a centrifuge, and the pressure was 4 to 13 kg/cllL2. Also, while continuing this pressurization, cool it down and remove it from the case for 10 minutes.
A 0φ billet was taken out and the particle distribution in it was investigated, and the attached photos (a) to (e) are micrographs taken at a magnification of 400 times and correspond to experiments 1 to 5 in Table 2. It was confirmed that each particle was uniformly dispersed.

The 100φ billet obtained in Experiments 1 and 2 in Table 2 above was hot extruded into a 20φ round bar, and the mechanical properties and coefficient of thermal expansion were measured. Table 3 below shows the standard values for the material, and it was confirmed that the tensile strength was approximately the same as that of the matrix material, but the coefficient of thermal expansion was significantly lower.

Table 3 Samples obtained in Experiment 3.5 and wear resistance A
Table 4 below shows the test results of JIS A4032, which is an alloy, with a hard chrome plated material using a Frictron friction and wear tester. Pressure 150 kg/c
m”, and the friction distance is 5000 m.

That is, the material of the present invention according to Experiment 3.5 is the comparative material A4.
The amount of wear is less than that of 032, and the coefficient of friction is also lower. That is, according to the present invention A 4032
It has better lubricity and wear resistance.

As shown in Table 4 of the present invention, the performance enhanced by the composite particles varies depending on the characteristics of the particles, but some examples of the performance of such particles are as follows. be.

Si3N4 particles: low thermal expansion, wear resistance Si particles: wear resistance, low thermal expansion graphite particles: vibration absorption, lubricity, high elasticity, Pb particles: lubricity, machinability ゛Select solid particles with these characteristics. By combining these properties, the properties required of the materials obtained become extremely diverse, and exhibit properties suited to each application. Typical properties and their uses are shown in Table 5 below, and the products of the present invention, which can be uniformly dispersed by appropriately selecting solid particles and compositing them, fully exhibit their properties. However, it is clear that the applications of aluminum-based alloys can be greatly expanded.

Table 5 "Effects of the Invention" According to the present invention as explained above, the particulate property reinforcing material is uniformly dispersed in the aluminum matrix and densely integrated to effectively exhibit the respective properties of the aluminum material. This invention enables the accurate provision of composite materials and is industrially highly effective.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and show micrographs at a magnification of 400 times of each product according to manufacturing examples according to the present invention, in which (A) is Experiment 1, (B) is Experiment 2, (C) is from Experiment 3, (D') is from Experiment 4, and (E) is from Experiment 5. Patent applicant: Nippon Light Metal Co., Ltd. Inventor: Kami 1
) Tetsuo Dou Nobuyuki Proceedings Amendment (Manninri Showa Wo, 5゜ thing. Japan)

Claims (1)

[Claims] a step of preparing an inorganic fiber material as hair spherical aggregates;
Particles with a particle size of 1 to 100μ are added to the
% or more, and a step of adding molten aluminum or aluminum alloy to the bulb-shaped fiber material to which the reinforcing material particles have been adhered and mixed, and permeating the aluminum or aluminum alloy under pressure. Manufacturing method for reinforced composites.